The present invention relates to the optical device and, more particularly, to an optical device using a two ultra-wide lenses facing in opposing directions that utilize a single image sensor to convert an optical signal to an electrical one.
A number of components are utilized to digitally capture video and images, where the selection and arrangement of components dictates a quality of a captured information/imagery, an amount of processing needed to convert a raw capture into a desired form, a bill of materials required for the capture device, and the like. Traditional cameras pair one sensor per lens, so that the light directed trough the optics of a single lens falls upon a light sensitive region of a sensor to be converted into information. This one-to-one arrangement has advantages of simplicity and scalability.
As a number of lenses and sensors increases, however, the arrangement suffers from multiple issues. For instance, many devices (such as wearables, portable cameras, mobile phones, and internet-of-things devices) have a small footprint, which results in a challenge placing all necessary components (including processor, battery, multiple lenses, and multiple image sensors) within a space limited footprint challenging. These challenges based on footprint are exasperated by functional layout constraints related to what feasible layouts are viable given variances in power, heat, and other tolerance specific considerations, which often vary from component to component of a circuit board.
These challenges of board layout are further complicated when different lenses face in different directions, since the sensor is typically located directly behind (orthogonal to the direction of light) a lens. Multiple lens arrays with a one-to-one lens/sensor correspondence are often spherical, having multiple small circuit boards including an image sensor on a horizontal surface, where the planes of the different small boards are significantly angled relative to each other. This type of arrangement, though practical or even preferred in many use cases, is disfavored in others as use of a flat circuit board with all components printed on a single side substantially reduces manufacturing cost, footprint, and structural complications introduced by optical component requirements.
Timing issues also exist for devices having multiple lenses that capture images designed to be digitally stitched together. For instance, in a video capture scenario, a timing of frames representing video content of a dynamic scene obtained from different sensors must be synchronized, otherwise a resulting stitched image will have movement/timing based errors. This is particularly problematic with panoramic lens arrangements as slight image discrepancies based on timing may greatly diminish an accuracy of a surround image in a user appreciable manner. Some digital signal processing manipulations can be utilized, each of which results in an increased cost in terms of computing cycles and latency of a produced image. In real time and near-real time surround mode (panoramic) video capture situations processing induced latency can be a significant issue affecting a viability of a video system.